Blood pressure and transcranial ultrasound predict moyamoya vasculopathy in Down syndrome

Abstract Aim To evaluate the feasibility of a stepwise, non‐invasive screening framework integrating blood pressure measurement with transcranial Doppler ultrasonography. Method In this prospective single‐site cohort study, 793 individuals with Down syndrome aged 8 to 26 years underwent standardized blood pressure assessment. Comparisons with National Health and Nutrition Examination Survey 2017–2018 were restricted to participants aged 8 years to younger than 18 years and performed using survey‐weighted regression. A smaller cohort of 111 participants underwent repeat blood pressure assessment, awake transcranial Doppler ultrasonography, and confirmatory magnetic resonance imaging/angiography. Results Among 988 screened participants, 793 were enrolled (mean age 16 years 7 months [SD 4 years 6 months]; 414 females, 378 males, and one participant of unknown sex). Mean systolic blood pressure centile was 44.7 in Down syndrome and 42.6 in the comparison cohort (difference 2.07 points, 95% confidence interval [CI] −1.12 to 5.26; p = 0.200). Diastolic blood pressure centile was higher in Down syndrome (difference 12.21 points, 95% CI 8.88–15.53; p < 0.001). Of the 111 participants who completed transcranial Doppler ultrasonography, 10 required repeat acquisition. Higher blood pressure was associated with higher mean middle cerebral artery velocity (75.5 vs 65.7 cm/s; p = 0.006). Imaging identified asymptomatic moyamoya syndrome in four participants. Interpretation A stepwise approach incorporating blood pressure and transcranial Doppler ultrasonography is feasible for cerebrovascular surveillance in Down syndrome. These findings support development of scalable screening strategies and warrant multicenter validation.